Hydraulic system for stabilizers



Aug. 7, 1945. F. w. TAYLOR 2,381,162

HYDRAULIC SYSTEM FOR STABILIZERS Filed Dec. 24, 1941 WITNESSES! INVENTORPatent ed Au 7, 1945 2,381,162

umrw STATES PATENTOFFHGE Frank W Taylor, sprmmem, Mm "donor toWeofiinghomse Electric communal. me me burgh, We, a oorpomllonn oi?lleumylvanle,

Amlloellom Ember 24%, 19411, Serlol No. $4M? v mm (on. Ml llll -Mylnventlon relal'ee to hydmmllc eystemc for, showing a palm in eocordencewith my lnvemstabilizers and the like and lit has for an object lionlull-e assembled form; to provide Improved apparatus of this character.Fig. 2 is a section on line H-H of Fig. 4.

subject to the opposed eotlon'ol two liquid preeme. e is e schematicView of one form of syssures to efl'ect relative adjustment of theelement lem to which my lnvenlion lo edoplelole; the nd support, twosources for supplying liquid unsection of the my being oubslemlilellv onthe dam pressure to the hydraulic meme together with llne Iv-w of lllg.l.

valves for the respectlvesoulcea end operative to Relemne to th d a ng.to descripti n 0f th secure ouch relations of euppllecl pressures as tolmml will WWW e m actuate the hydraulic means for stabilizing the Amotor M heo turned no its end bell an em element in relation to thesupport melee groove 8 lnl'o whlch ls fitted e ring mem- A furtherobject of She lzzwezmtlolzzl is to pmbe! 8 Within the opposite end ofwhich ls eeelecl vlale, for on element plvomlly mounted on a againsteohoulder the flange-like portion 43 of a. support end coupled to theletter by reelpoocelclxculer plate 5, the entire assembly leelng eelnohydraulic means subject to fihe opposed eeowed to the motor by means ofbelle l extendtlon of two liquid pressures to efiece relemvo me throughholes in eeld flange, the lhrwded adjustment, of me element end ort, m2o emls of said bolts enewing mpmd holes in the sources eupplylng liquidunder pressure eo vthe mole? housing end "bell. Circular golele 5 formshydraulic meme together with velvea for the we base ol the plmm havingtherein manage for actuate the hydraulic meens for efiectllee poolthisgem" train is clflvem by the motor M; lte tlonel adjmtment of theelement eml ewepom. axle heme ellanecl Willa the molar ehefe 20 to Afurther object is to provide means for fun receive email have keyedwithin a bore m its etude nlshlne two euppllee of motive liquid wag uiteshell; M the end of the mo shell; Ell lo Meet 62- able reletlvepressures to secure actuation of e lest drive by the motor. A'clrculermete 223, of e servo-motor and wherein lbhe measures are elm thicknessto provide aim-1w; 'cleamnce for the multeneouely changed by valves feethe memegems, has openings 36, 87] end 28 for the gears tlve suppliesend which velvee are under con= extending therethromxh, The p mp 1 m istrol of a'contx-ol member movable 11m ogaposlle dlcomplelzed by eclrculer mole of cover plate ll rectlone feomemean position. positionededjeoent to me plate 528 end lwwlme sun another object of the inventionlo to pro redlel oil m es 2%, 2. a n all fo ed h I vlde twoslmulteneously opemtlng and poeltlv e= m, the za eeeeeee 82. and 88serving es pump indlsnlecemenl; pumps Whose outlet or supply peelet p eee d e pw eee 89 ene (32 ee pump sag h?| e liquid bypassed therefrom bymeans of outlet or supply pemew. The come-cling sur 3) ages providedwith valves operated by an acfaces of the plates comprising Ema mmineledcon tuatoz' moved for this urpose in response lo p-os m tlon we groundl0 pr i ill l-l ght seal sltlon ole, control member, the arrangement bewhen brought into contact. The eeeembly ls ing such that, with thecontrol member in mean bolted together y a plurality f bolls 33wwposltlom'lhe valves are positioned for themaln me through plates 23and M and! we tenance of e predetrmlnecl'relatlon of pressures g ggfiggp glggss fllfgrzgldfllifiped 131:: g;

3, are preferably drilled so that thelrradlel exee and the the 2e m, asand 2e dulled-vertically so as to provide direction of departure. 4 2a a1mm outle 22 and Further objects and advantegea will become p mew and mp ts more apparent from. a study or the following The pump housing alsoforms one wall 01' the specification when considered ln'conJunctlon withn reservoir ll, it cover plate '8! having open 4 the accompanyingdrawing, in which: lugs 40 and 44 connecting the reservolz to the 111-mme 1 m a section on line 14 of m. 4 letpassages a: and a sothatthelatter function in action on the oil in lubricating fluid throughthe limit opening as ump inlet or suction passages communicating withthe reservoir.

Assuming for the moment, rotation of the gears as indicated by thearrows in Fig. 2, it will be seen that in the spaces 33 and 31 where thegear teeth come into mesh, that a squeezing-out action on the oil inthose spaces will occur, and conversely, in the spaces 33 and 3| wherethe teeth of the gears are disengaged. a pulling or suckingthat spacewill occur. The pressure or outlet oil ports of the pump will,therefore, be located in the spaces 33 and 31 while the inlet ports willbe located in the spaces 33 and II. By using the three gears in train,as shown, two simultaneously-operative, positivedisplacement and equalcapa'city pumps result and which are formed as a single compact unit toprovide two separate sources of liquid pressure.

The sump, or oil reservoir side of the'cover plate 3|, is connected tothe-radial oil passages 33, 32, 33 and 33 by holes drilled verticallyinto this face of plate 3| into the oil passages. The holes 33 and 42tapped into the pressure or supply passages are drilled to 33 and 35 inthe base 31 of the magnetic valve assembly 39 mounted on the reservoirside of plate 3|, to form by-pass passages for the pump outlet ordischarge passages for lay-passing liquid from the latter to thereservoir. The holes 33 g 3Vleading into the inlet passages netic valveassembly is sealed within the reservoir chamber 5|. A sealing plate 33is bolted to the motor side of plate 3 and is of sufllcient dimeterthat. a gasket 33 shall include within its seal the three bearings ofthe ear train l3, l1 and H. A small chamber 33 is provided within theoil seal of late 33 for the p p se of permitting circulation of the oilthrough the stub shaft bearings, said chamber being connected to thesump or oil reservoir through holes 33 and 33 drilled completely throughthe laminated pump housing assembly. A packing gland 31 about the motorshaft'tl completes the seal of thechamber. Such small leakage as mayoccur through packing gland 33 is drained from the motor pump assemblythrough a hole 33 in the ring 3. The above construction permitscirculation of the stub shaft bearings, their bindingr to which the pumpis particuthereby preventing A type of system larly adapted is currentfurnished. by a battery 3| or other source of energy is normally equallydivided between the right and left-hand portion of a resistor 32, sinceit forms parallel. paths extending, respectively, through valveactuating coils 33 and '33. Two valves 31 and 33, cooperating with seatsprovided in-the by-pass passages and facing in the directions of flowthrough the latter, are interconnected by a common valve actuatingelement 1| pivoted at 13 and which abuts the valves to and 33 whichactuate the element the poppet or seated'type valves 31 and 33. The

schematically shown in Fig. 4. A

opposite faces of reciprocates,

align with the oil holes pump outlet orsupply passages 33 and 33 areconnected by the supply pipes 13 and 13 to the lower and upper portions,respectively, of the cylinder 11. Sincems has been stated, the valvesare normally open to a predetermined relative extent, as

- packing seal.

- placement ment of the actuatin ressure differences may occur lowerpressure determined by the normal position of the actuator or rocker 1|,the fiuid pressures on op sides of the piston 3| are in such relation asto keep the piston in a fixed position. As a consequence thereof, therewill be no torques exerted by the piston element being stabilized andconsequently such maintained in its angul r position with respect to theforces exerted by liquid pressures acting on the piston 3| are inequilibrium, the piston remains in fixed position; however, withreciprocal movement of the valves in relation to their seats, one valvemoving in a closing direction and-the other in an opening direction,flows through the by-pass passages are correspondingly varied and thedifferential pressure condition thereby created causes piston movement.A leakage line 33 is connected to theoil reservoir chamber 3| and leadsthe packing seal through which the piston rod so that as excessivepressure is (1* in the piston chamber, oil will leak into the line 33insteadof being forced through the device 31 comprising a plurality oflexible contact members resistor 32 is operated by the actuating (orpilot) element 33, and is herein used to unbalance the currents in valveactuating coils 33 and 33. As shown. the leaf spring contacts 3!, arearranged as right-hand and left-hen groups with the actuating element 33therebetween. For the function of this controlling device with referenceto the velocity of dis t and disof a gun, or element to be stabilized,reference may be had to a eopending application of C. R. Hanna, SerialNo. 366,817, filed Nov. 23. 1940, entitled "Gun stabilizers." For thepurpose of my description, however, the contact actuating element 39 maybe assumed to be controlled provement in plication is confined to thepump s m. Moveelement 33 to the left will close the contacts 3| of theleftwhile o ening those of the rightdecreasing the resistance throughportions of resistor 3| while inprogressively hand group connection withthe element or body whose position is controlled, will rotate saidelement or body'clockwise to decrease its elevation angle. Movement ofthe piston in either direction due to as liquid at the side is expel edby through the associated supp charged "through its lily-passfor thereason that spect to its seatjan orifice and presents an area subject tothe upstream As each orifice is restricted, the u stream pressure isincreased to increasethe fluid ressure about the trunnion axis 33 of thedirectly thiOllih t pp on this instance over said patentappressureofthelatters aesaiez force acting on the valve. Movement ofthe actuating member H in consequence of a change in the relation ofmagnetic forces due to a disturbance is accompanied by an opposed changein the relation of the fluid pressure forces with the result that theactuating member has an equilibrium-seeking tendency. Whenever thecontrolling member 89 ceases to change its position to change thecurrent value of the supplies for the windings 63 and 65, the magneticforces of the latter cease to change and equilibrium of the actuatingmember H is attained when the clockwise moments due to magnetic andfluid pressure forces exerted on the latter are equal to thecounterclockwise moments. Movement of the actuating element 89 to theright obviously has the opposite effect on the contacts and thehydraulic means controlled thereby.

The stabilizer is equipped with an additional feature of controlpreventing substantial deviation or departure of the element or gun fromwanted position when subject to the effect of unusually largeunbalancing torques, such as those due to gun recoil and which may be ofa magnitude many times larger than those normally acting on the system.Since the relatively short periods of recoil, usually of one-half secondduration, render impractical the construction of a system suflicien'tlylarge to cope with these unbalances, an additional coil 93 has beenadded to the pole piece controlling valve 61, and is connected in serieswith the battery 60. A recoil switch 95 normally biased closed by a sping, is maintained open by the gun breech and closed during recoil whenthe gun breech recedes therefrom, energizing the valve coil 93 andfirmly closing valve 61, diverting full pressure of the associated sideof the pump to the bottom chamber of cylinder ll, thus firmly couplingthe gunto its mount and supporting it during the recoil period. A ballor check valve 91 is installed in the pump output which leads to thebottom portion of the cylinder chamber to prevent the back pressureexerted by the piston during recoil unbalance from entering the pumpwhen it is in excess of the peak delivery of the pump. Thehydraulicpressures in the cylinder '71 are controlled by theirrespective valve currents. As the stiffness regulator resistor 99 isadjusted to increase the valve currents and magnetic flux densities,negative stiffness is also increased. Regarding the definition of"stiffness," a body is said to have positive stiffness if its resistanceincreases upon compression, such as is inherent in a spring. Anelectromagnet has negative stifiness, since, as the armature is attracted toward the core, a smaller and smaller force is required. Ifsuch negative stiil'ness increases beyond the positive stiffness,arising from the hydraulic pressure on the valves, unstable operationoccurs. The range of instability may be varied by changing the valveclearances, air gaps, or other constants and may be kept low by keepingthe total valve currents at a minimum value. Relief valves IM and I03are installed in pressure outlets connectedto the sump for the purposeof preventing air from being pumped or drawn into the hydraulic system,in the event the gun should be moved in elevation manually. The

mechanical advantage in this case would be largeand the pumping actionof 'the'piston could possibly draw air through any of the oil lineconnections. a

The pump design as shown, is simple in construction and has few wearingparts. It forms, in effect, two separate pumps, but has the adill)vantage of being a compact unit requiring but one motor for-its drive.

I am, of course, aware that others, particularly after having had thebenefit of the teachings of my invention, may devise other devicesembodying my invention, and, I, therefore, do not wish to be limited tothe specific showings made in the drawing and the descriptive disclosurehereinbefore made, but wish to be limited only by the scope of theappended claims.

I claim as my invention:

1. In apparatus providing two simultaneouslyeffective supplies of motiveliquid for a pressureresponsive device, first and secondsimultaneously-operating, positive-displacement gear pumps; a reservoirfor liquid; passages for the supplies of liquid open to the outlets ofthe respective pumps; pump inlet passages communieating with thereservoir; bypass passages for conducting liquid from the respectivesupply passages to the reservoir and having valve seats facing in thedirection of flow therethrough; a pair of valves movable toward and awayfrom said seats to change the flows through the by-pass passages inorder to change the supply passage pressures; mechanism for so that theforce of liquid pressure applied to one valve is opposed by that appliedto the other; said mechanism including a rocker, stems connected to thevalves and abutting opposite ends of the rocker, and pivot means for thecentral portion of the rocker and reacting to oppose liquid pressureforces exerted thereon: a" controlling member movable in oppositedirections from a mid position; and means for applying oppositely-actingtilting forces to saidconnecting mechanism and responsive to departureof the controlling member from mid position in opposite directions tovary the tilting forces relatively to control the positions of thevalves relative to their seats and consequently the relative liquidpressures in said supply passages so as t trolling member in midposition, for a predetermined relation of pressures in the supplypassages and to provide, with departure of the controlling member frommid position, for increase in one supply passage pressure and decreasein the other supply passage pressure according to the direction andextent of departure.

2. The combination as claimed in claim 1 wherein the pumps are of equalcapacity and are comprised by two gears individual to the pumps andmeshing with an intermediate gear common to the pumps.

3. The combination as claimed in claim 1. wherein at least one of thesupply passages is provided with a check valve opening away from theassociated pump outlet.

4. In apparatus providing two simultaneouslyefiective supplies of motiveliquid for a pressureresponsive device, first and secondsimultaneously-operating, positive-displacement and equalcapacity gearpumps; passages for the supplies of liquid open to the outlets of therespective pumps; a reservoir for liquid; pump inlet passagescommunicating with the reservoir; byepass passages for conducting liquidfrom the respective supply passages to the reservoir and having valveseats facin in. the direction of flow therethrough; a pair of valvesmovable toward and away from said seats to change the flows through thebychange the supply pas sage pressures; mechanism for connecting said ofliquid pressure applied to one valve is opposed by that applied toconnecting said valves provide, with the con- 3 asemee the other; saidconnecting mechanism including a rocker, stems connected to the valvesand abutting opposite ends of the rocker, and pivot means for thecentral portion of the rocker and reacting to oppose liquid pressureforces exerted thereon; a controlling member movable in oppositedirections from a mid position; a pair of electro-magnets for applyingoppositely-acting tilting forces to the connecting mechanism; a pair ofcircuits for supplying electrical energy in parallel from a suitablesource to the windings of the electro-Inagnets; and variable resistancesin the circuits and cooperating with the controlling member to varyrelatively the oppositely-acting tilting forces applied to theconnecting mechanism to control the positions of the valves relative totheir seats and consequently the relative liquid pressures in saidsupply passages so as to provide, with the controlling member in midposition, for a predetermined relation of pressures in the supplypassages and to provide, with departure of the controlling member frommid position, for increase in one supply passage pressure and decreasein the other according to the direction and extent of departure.

5. In apparatus providing two simultaneouslyefiective supplies of motiveliquid for a pressureresponsive device, first and second pumpscomprising a pair of gears meshing with an intermediate gear and ahousing for the gears; a reservoir for liquid; said housing forming oneof the walls of the reservoir and including a cover plate; a pair ofpump inlet passages formed in the cover plate and communicating with thereservoir; a pair of passages for the liquid supplies havin portionsformed in the cover plate and open to the outlets of the pumps; by-passpassages formed in the cover plate for conducting liquid from the supplypassages to the reservoir and having valve seats facing in thedirections of flow therethrough; a pair of valves movable toward andaway from said seats to vary the flows through the by-pass passages inorder to vary the supply passage pressures; an actuating member abuttingthe valves, cooperating with the latter so that the force of liquidpressure applied to one valve is opposed by that applied to the other,and operative to move the valves in a reciprocal manner; a controllingmember movable in opposite direction irom a mid position; and means forapplying oppositely-acting forces to the actuating member and responsiveto departure of the controlling member from mid position in oppositedirections to control the positions of the valves relative to theirseats and consequently the relative liquid pressures in said supplypassages so as to provide, with the controlling member in mid position,for a predetermined relation of pressures in the supply passages and toprovide, with departure of the controlling member from mid position, forincrease in one supply passage pressure and decrease in the otheraccording to the direction and extent of departure.

6. The combination as claimed in claim 5 wherein the cover plate isprovided with ports connecting the supply passages and the reservoir andcheck valves to close the ports in response to pressures in the supplypassages and developed by the pumps.

7. In apparatus providing two simultaneouslyeffective supplies of motiveliquid for a pressureresponsive device, first and second pumpscomprising a pair of gears meshing with an intermediate gear and ahousing for the gears; a reservoir for liquid; said housing forming oneof the walls of the reservoir and including a base plate and a coverplate; journals connected to the gears and fitting bearings extendingthrough the base plate; a driving shaft connected to one of thejournals; a plate having sealed attachment with respect to the outerface of the base plate and having an opening through which the drivingshaft extends; a packing gland having sealing relation with respect tothe driving shaft and carried by the sealing plate in order that thelatter may form, with respect to the base plate, a sealed chamber opento the outer ends of said bearings; at least one passage formed in saidhousing for connecting said sealed chamber to the reservoir; a pair ofpump inlet passages formed in said cover plate and communicating withthe reservoir; a pair of passages for the supplies of liquid includingportions formed in said cover plate and open to the outlets of therespective pumps; by-pass passages formed in said cover plate forconducting liquid from the supply passages to the reservoir and havingvalve seats facing in the directions of flow therethrough; :i pair ofvalves movable toward and away from said seats to vary the flows throughthe by-pass passages in order to vary the supply passage pressures; anactuating member abutting the valves, cooperating with the latterso thatthe force of liquid pressure applied to one valve is opposed by thatapplied to the other, and operative to move the valves in a reciprocal*manner with respect to their seats; a controlling member movable inopposite directions from a mid position; and means for applyingoppositely-acting forces to the actuating member and responsive todeparture of the controlling member from mid position in oppositedirections to control the positions of the valves relative to theirseats and consequently the relative liquid pressures in said supplypassages so as to provide, with the controlling member in mid position,for a predetermined relation oi. pressures in the supply passages and toprovide, .With departure of the controlling member from mid position,for increase in one supply passage pressure and decrease in the otheraccording to the direction and extent of departure.

' FRANK W. TAYLOR.

